Concomitant Boost Radiotherapy Compared with Conventional Radiotherapy in Squamous Cell Carcinoma of the Head and Neck — a Phase III Trial from a Single Institution in India

Abstract Aims To test the efficacy of an accelerated fractionation schedule (concomitant boost) against standard conventional fractionation in squamous cell carcinomas of the head and neck region in our patient population. Materials and methods Patients were randomised to receive either conventional radiotherapy with 2 Gy/fraction/day, to a dose of 66 Gy in 33 fractions over 6.5 weeks or accelerated radiotherapy in the form of concomitant boost to a dose of 67.5 Gy/40 fractions over 5 weeks (phase 1: 45 Gy/25 fractions/5 weeks and phase 2: 22.5 Gy/15 fractions/3 weeks as a second daily fraction after a 6 h gap). The primary and secondary end points were disease-free survival and locoregional control respectively. Results The compliance was 97.2% and 96.5% in the concomitant boost and conventional arms, respectively. Patients treated with concomitant boost had a better 2-year disease-free survival (71.7% vs 52.17%, P = 0.0007) and locoregional control rates (73.6% vs 54.5%, P = 0.0006) than with conventional fractionation. On exploratory subgroup analysis, the oropharynx ( P < 0.001), T4 lesions ( P = 0.017), N+ disease ( P < 0.001) and stage IV disease ( P < 0.001) were statistically significant prognostic variables in favour of the concomitant boost arm. Grade 3 mucositis was seen in 35% of patients in the concomitant boost arm, whereas in the conventional arm only 19% of patients had grade 3 mucositis ( P = 0.01). The median radiotherapy duration in the concomitant boost arm was 36 days (range 36–53 days), whereas in the conventional arm it was 46 days (range 46–64 days). The mean gap in radiation treatment in the concomitant boost arm was 1.68 days (range 0–14 days), whereas the mean gap in the conventional arm was 1.58 days (range 0–14 days). Conclusions Concomitant boost is a therapeutically superior and logistically feasible accelerated radiotherapy regimen in advanced head and neck cancers, especially in the setting of a developing country.